3,160 research outputs found
Networks of Gratitude: Structures of Thanks and User Expectations in Workplace Appreciation Systems
Appreciation systems--platforms for users to exchange thanks and praise--are
becoming common in the workplace, where employees share appreciation, managers
are notified, and aggregate scores are sometimes made visible. Who do people
thank on these systems, and what do they expect from each other and their
managers? After introducing the design affordances of 13 appreciation systems,
we discuss a system we call Gratia, in use at a large multinational company for
over four years. Using logs of 422,000 appreciation messages and user surveys,
we explore the social dynamics of use and ask if use of the system addresses
the recognition problem. We find that while thanks is mostly exchanged among
employees at the same level and different parts of the company, addressing the
recognition problem, managers do not always act on that recognition in ways
that employees expect.Comment: in Tenth International AAAI Conference on Web and Social Media, 201
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The family drug & alcohol court (FDAC) evaluation project
This report presents the findings from the evaluation of the first pilot Family Drug and Alcohol Court (FDAC) in Britain. FDAC is a new approach to care proceedings, in cases where parental substance misuse is a key element in the local authority decision to bring proceedings. It is being piloted at the Inner London Family Proceedings Court in Wells Street. Initially the pilot was to run for three years, to the end of December 2010, but is now to continue until March 2012. The work is co-funded by the Department for Education (formerly the Department for Children, Schools and Families), the Ministry of Justice, the Home Office, the Department of Health and the three pilot authorities (Camden, Islington and Westminster). The evaluation was conducted by a research team at Brunel University, with funding from the Nuffield Foundation and the Home Office. FDAC is a specialist court for a problem that is anything but special. Its potential to help break the inter-generational cycle of harm associated with parental substance misuse goes straight to the heart of public policy and professional practice. Parental substance misuse is a formidable social problem and a key factor in around a third of long-term cases in children’s services in some areas. It is a major risk factor for child maltreatment, family separation and offending in adults, and for poor educational performance and substance misuse by children and young people. The parents’ many difficulties create serious problems for their children and place major demands on health, welfare and criminal justice services. For these reasons, parental substance misuse is a cross-cutting government agenda. FDAC is distinctive because it is a court-based family intervention which aims to improve children’s outcomes by addressing the entrenched difficulties of their parents. It has been adapted to English law and practice from a model of family treatment drug courts that is used widely in the USA and is showing promising results with a higher number of cases where parents and children were able to remain together safely, and with swifter alternative placement decisions for children if parents were unable to address their substance misuse successfully. The catalysts for the FDAC pilot were the encouraging evidence from the USA and concerns about the response to parental substance misuse through ordinary care proceedings in England: poor coordination of adult and children’s services; late interventions to protect children; delays in reaching decisions in court; and soaring costs of proceedings, linked to the cost of expert evidence.The work is co-funded by the Department for Education (formerly the Department for Children, Schools and Families), the Ministry of Justice, the Home Office, the Department of Health and the three pilot authorities (Camden, Islington and Westminster).1 The evaluation was conducted by a research team at Brunel University, with funding from the Nuffield Foundation and the Home Office
Dispersal and population structure at different spatial scales in the subterranean rodent Ctenomys australis
This study was funded by grants from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, PIP5838), Agencia de Promoción Científica y Tecnológica de la Argentina (PICTO1-423, BID-1728/OC-AR), and the programme ECOS-Sud France/Argentina (A05B01).Background: The population genetic structure of subterranean rodent species is strongly affected by demographic (e.g. rates of dispersal and social structure) and stochastic factors (e.g. random genetic drift among subpopulations and habitat fragmentation). In particular, gene flow estimates at different spatial scales are essential to understand genetic differentiation among populations of a species living in a highly fragmented landscape. Ctenomys australis (the sand dune tuco-tuco) is a territorial subterranean rodent that inhabits a relatively secure, permanently sealed burrow system, occurring in sand dune habitats on the coastal landscape in the south-east of Buenos Aires province, Argentina. Currently, this habitat is threatened by urban development and forestry and, therefore, the survival of this endemic species is at risk. Here, we assess population genetic structure and patterns of dispersal among individuals of this species at different spatial scales using 8 polymorphic microsatellite loci. Furthermore, we evaluate the relative importance of sex and habitat configuration in modulating the dispersal patterns at these geographical scales. Results: Our results show that dispersal in C. australis is not restricted at regional spatial scales (similar to 4 km). Assignment tests revealed significant population substructure within the study area, providing support for the presence of two subpopulations from three original sampling sites. Finally, male-biased dispersal was found in the Western side of our study area, but in the Eastern side no apparent philopatric pattern was found, suggesting that in a more continuous habitat males might move longer distances than females. Conclusions: Overall, the assignment-based approaches were able to detect population substructure at fine geographical scales. Additionally, the maintenance of a significant genetic structure at regional (similar to 4 km) and small (less than 1 km) spatial scales despite apparently moderate to high levels of gene flow between local sampling sites could not be explained simply by the linear distance among them. On the whole, our results support the hypothesis that males disperse more frequently than females; however they do not provide support for strict philopatry within females.Publisher PDFPeer reviewe
Going beyond the Kaiser redshift-space distortion formula: a full general relativistic account of the effects and their detectability in galaxy clustering
Kaiser redshift-space distortion formula describes well the clustering of
galaxies in redshift surveys on small scales, but there are numerous additional
terms that arise on large scales. Some of these terms can be described using
Newtonian dynamics and have been discussed in the literature, while the others
require proper general relativistic description that was only recently
developed. Accounting for these terms in galaxy clustering is the first step
toward tests of general relativity on horizon scales. The effects can be
classified as two terms that represent the velocity and the gravitational
potential contributions. Their amplitude is determined by effects such as the
volume and luminosity distance fluctuation effects and the time evolution of
galaxy number density and Hubble parameter. We compare the Newtonian
approximation often used in the redshift-space distortion literature to the
fully general relativistic equation, and show that Newtonian approximation
accounts for most of the terms contributing to velocity effect. We perform a
Fisher matrix analysis of detectability of these terms and show that in a
single tracer survey they are completely undetectable. To detect these terms
one must resort to the recently developed methods to reduce sampling variance
and shot noise. We show that in an all-sky galaxy redshift survey at low
redshift the velocity term can be measured at a few sigma if one can utilize
halos of mass M>10^12 Msun (this can increase to 10-sigma or more in some more
optimistic scenarios), while the gravitational potential term itself can only
be marginally detected. We also demonstrate that the general relativistic
effect is not degenerate with the primordial non-Gaussian signature in galaxy
bias, and the ability to detect primordial non-Gaussianity is little
compromised.Comment: 13 pages, 5 figures, published in PR
Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
We forecast the sensitivity with which the Murchison Widefield Array (MWA)
can measure the 21 cm power spectrum of cosmic hydrogen, using radiative
transfer simulations to model reionization and the 21 cm signal. The MWA is
sensitive to roughly a decade in scale (wavenumbers of k ~ 0.1 - 1 h Mpc^{-1}),
with foreground contamination precluding measurements on larger scales, and
thermal detector noise limiting the small scale sensitivity. This amounts
primarily to constraints on two numbers: the amplitude and slope of the 21 cm
power spectrum on the scales probed. We find, however, that the redshift
evolution in these quantities can yield important information about
reionization. Although the power spectrum differs substantially across
plausible models, a generic prediction is that the amplitude of the 21 cm power
spectrum on MWA scales peaks near the epoch when the intergalactic medium (IGM)
is ~ 50% ionized. Moreover, the slope of the 21 cm power spectrum on MWA scales
flattens as the ionization fraction increases and the sizes of the HII regions
grow. Considering detection sensitivity, we show that the optimal MWA antenna
configuration for power spectrum measurements would pack all 500 antenna tiles
as close as possible in a compact core. The MWA is sensitive enough in its
optimal configuration to measure redshift evolution in the slope and amplitude
of the 21 cm power spectrum. Detecting the characteristic redshift evolution of
our models will confirm that observed 21 cm fluctuations originate from the
IGM, and not from foregrounds, and provide an indirect constraint on the
volume-filling factor of HII regions during reionization. After two years of
observations under favorable conditions, the MWA can constrain the filling
factor at an epoch when ~ 0.5 to within roughly +/- 0.1 at 2-sigma.Comment: 14 pages, 9 figures, submitted to Ap
Estimating CDM Particle Trajectories in the Mildly Non-Linear Regime of Structure Formation. Implications for the Density Field in Real and Redshift Space
We obtain approximations for the CDM particle trajectories starting from
Lagrangian Perturbation Theory. These estimates for the CDM trajectories result
in approximations for the density in real and redshift space, as well as for
the momentum density that are better than what standard Eulerian and Lagrangian
perturbation theory give. For the real space density, we find that our proposed
approximation gives a good cross-correlation (>95%) with the non-linear density
down to scales almost twice smaller than the non-linear scale, and six times
smaller than the corresponding scale obtained using linear theory. This allows
for a speed-up of an order of magnitude or more in the scanning of the
cosmological parameter space with N-body simulations for the scales relevant
for the baryon acoustic oscillations. Possible future applications of our
method include baryon acoustic peak reconstruction, building mock galaxy
catalogs, momentum field reconstruction.Comment: 25 pages, 11 figures; reference adde
Temperature independent band structure of WTe2 as observed from ARPES
Extremely large magnetoresistance (XMR), observed in transition metal
dichalcogendies, WTe, has attracted recently a great deal of research
interests as it shows no sign of saturation up to the magnetic field as high as
60 T, in addition to the presence of type-II Weyl fermions. Currently, there
has been a lot of discussion on the role of band structure changes on the
temperature dependent XMR in this compound. In this contribution, we study the
band structure of WTe using angle-resolved photoemission spectroscopy
(ARPES) and first-principle calculations to demonstrate that the temperature
dependent band structure has no substantial effect on the temperature dependent
XMR as our measurements do not show band structure changes on increasing the
sample temperature between 20 and 130 K. We further observe an electronlike
surface state, dispersing in such a way that it connects the top of bulk
holelike band to the bottom of bulk electronlike band. Interestingly, similar
to bulk states, the surface state is also mostly intact with the sample
temperature. Our results provide invaluable information in shaping the
mechanism of temperature dependent XMR in WTe.Comment: 7 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1705.0721
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